The invention relates to computer implemented systems and processes to facilitate pre-operative planning and post-operative evaluations of image-guided brachytherapy procedures for treatment of prostate cancer.
Brachytherapy procedures for treatment of prostate cancer are well known. Brachytherapy involves treating cancer by precisely locating a plurality of radiation sources inside a human body in a three-dimensional array. The radiation sources generally are xe2x80x9cseedsxe2x80x9d of radioactive isotopes that are placed in the treatment area according to a seed placement plan.
At least four major steps are performed in a brachytherapy procedure. First, a transrectal ultrasound study of a patient""s prostate is made. Creation of the treatment plan is initiated with the capture of transversely oriented transrectal ultrasound images in any one of a plurality of known manners. The images identify the anatomical structures present in the treatment area, and their relative size and location. The volume of the structures is not necessarily calculated. Size assessment using visuals is relative and qualitative.
Second, using the captured images, a pre-operative seed placement plan is developed to determine the desired location of the seeds in a three-dimensional volume. A goal of the placement plan is to enable sufficient doses of radiation to impinge on the structures or portions of structures needing treatment, while attempting to avoid unnecessary amounts of radiation from impinging on other structures or portions of structures in the treatment area. General criteria for establishing seed placement plans is known. In general, the process of generating a seed placement plan involves proposing the location of a plurality of seeds in a three-dimensional volume, and based on the known radiation characteristics of the seeds, calculating the radiation dose levels within the treatment area and displaying isodose lines. Various iterations of the plan may be made in an attempt to optimize the plan. Each iteration requires a new dose calculation which can be time-consuming with known systems.
Once an acceptable plan is approved, the third step is to perform the brachytherapy procedure in a known manner. The seeds are delivered by the use of needles. This typically includes placing a needle guide template over the perineum to assist the physician in placing the seeds in the patient""s prostate. The needle guide template is a physical device of known geometry containing holes with half-centimeter spacing. The configuration of the template defines the geometry of the set of possible seed implants. The needle guide template is registered by identifying two known landmarks in the ultrasound image. This accounts for any relative translation, rotation, or scaling of the image study. The physical placement of seeds is effected by loading a plurality of needles each with a plurality of seeds, inserting the needles into the body, and releasing the seeds in an attempt to deliver the seeds according to the plan.
The fourth step is a post-operative evaluation procedure whereby the actual location of the seeds is determined and compared against the plan. To do this, images of the treatment area are taken, such that from the images, the actual seed locations can be identified and compared to the planned location for each seed. Various problems arise in attempting to identify the seeds. In part, this is because to find the three-dimensional array of seeds, the user must look at various image scans. If the length of a seed is greater than the distance between image scans, a seed may appear on multiple image scans. This can give rise to redundant seed identification in adjacent images. If the post-operative evaluation reveals that the actual seed locations varies from the pre-operative plan, corrective action may be necessary.
Computer implemented systems for assisting with some aspects of these procedures are known. Software for one such system is available from Multimedia Medical Systems, the assignee of the present invention, and others. One such system is known as MMS TherpacPLUS Version 6.5. Known systems are useful in assisting with certain aspects of the pre-operative plan and the post-operative evaluation, but have various limitations and drawbacks.
An object of the invention is to overcome the limitations and drawbacks of prior systems.
Another object of the invention is to provide computer implemented systems and processes to facilitate pre-operative planning and post-operative evaluations in brachytherapy procedures for treatment of prostate cancer including a graphical user interface that guides a user through a plurality of operations relating to pre-operative planning and post-operative evaluations where certain options are displayed or disabled based on previous choices made by the user.
Another object of the invention is to provide computer implemented systems and processes to facilitate pre-operative planning and post-operative evaluations in brachytherapy procedures for treatment of prostate cancer, where real-time image scans may be loaded (e.g., direct video capture from the ultrasound machine or video tape of the procedure, DICOM transfer, or magnetic digitization using a backlit magnetic digitizer tablet ) into the system for use with preparing a pre-operative plan or performing a post-operative evaluation.
Another object of the invention is to provide computer implemented systems and processes to facilitate pre-operative planning and post-operative evaluations in brachytherapy procedures for treatment of prostate cancer including a graphical user interface comprising a plurality of simultaneously displayed, linked windows, also know as a canvas layout, including a relatively larger window for displaying a single, relatively large ultrasound image in a sequence of ultrasound images and a plurality of relatively smaller windows that display thumbnail views of multiple ultrasound images in the sequence of ultrasound images. Selection of an individual image from the thumbnails in the canvas layout is reflected in the single, large window.
Another object of the invention is to provide computer implemented systems and processes to facilitate pre-operative planning and post-operative evaluations in brachytherapy procedures for treatment of prostate cancer that allows a user (e.g., a dosimetrist or physician) to place the seeds (1) individually, (2) in an alternating configuration along a single needle, or (3) using one of a plurality of automatic seed placement routines. The user can modify the seed placement pattern, for example, one generated by an automatic seed placement routine, by overlaying a graphical representation of a needle guide template on each image scan of the anatomical structure, rather than on the entire area of the image scan of the patient, to aid in performing the pre-operative planning and post-operative evaluation.
Another object of the invention is to provide computer implemented systems and processes to facilitate pre-operative planning and post-operative evaluations in brachytherapy procedures for treatment of prostate cancer that enables real-time dose calculations to be performed as a pre-operative plan is altered, and where a dose matrix may be reconfigured over a specified area of the image scans to reduce the memory and time required to perform the calculations.
Another object of the invention is to provide computer implemented systems and processes to facilitate pre-operative planning and post-operative evaluations in brachytherapy procedures for treatment of prostate cancer where anatomical structures in the treatment area can be displayed in a three-dimensional view with solid surface area, and a color-wash of the anatomical structure displays the dose distribution over the surface area with particular isodose values being uniquely displayed.
Another object of the invention is to provide computer implemented systems and processes to facilitate pre-operative planning and post-operative evaluations in brachytherapy procedures for treatment of prostate cancer that reduces redundancy in seed identification during post-operative evaluation by identifying possibly redundant seeds, displaying a list of possibly redundant seeds to the user, and enabling the user to delete, merge or ignore the possibly redundant seeds.